Signs of Termites in walls September 13, 2016 Juan Broncano How do you know if you have termites in your wall? There are tell tale signs that are specific to termites. Cracking in walls can be a sign that something sinister is happening behind the wall. The mud spots confirm that it's termites. Termites will always seal any opening with their mud, here you can see tightly packed mud filling in the gaps. Subtle changes in timber cover strips can be a dead giveaway. Here the vertical timber strip and the one to the left has been eaten out, the strip on the right remains intact. Inside this built in wardrobe you can see evidence of termite workings. There is a tiny bit of mud right in the middle of the corner at the top and spots of mud/mould is visible on the Left Hand side. This is a clear indication of termite activity behind the walls.